1. Field of the Invention
The present invention relates to load supporting structures and more particularly relates to such structures having a rigid annular foot for supporting the load but aided by fluid pressure within the annulus to provide an air cushion which supports a large majority of the load to permit low frictional movement of the structure.
2. Description of the Prior Art
Load supporting structures which support different types of apparatus on a thin film of air acting on supporting surfaces while controlling the escape of air from below the load supporting structure are disclosed in the following U.S. patents:
U.S. Pat. No. 3,191,706, Peterson, Jun. 29, 1965 PA1 U.S. Pat. No. 3,592,285, Noble, Jul. 13, 1971 PA1 U.S. Pat. No. 3,598,198, Williams, Aug. 16, 1971 PA1 U.S. Pat. No. 3,780,823, Michaud et al, Dec. 25, 1973 PA1 U.S. Pat. No. 3,822,761, Vaughen, Jul. 9, 1974 PA1 U.S. Pat. No. 3,908,784, Blurton et al, Sept. 30, 1975 PA1 U.S. Pat. No. 4,273,244, Jensen et al, Jun. 13, 1981
None of the above described references disclose a rigid annular foot that encloses an air cushion therein, and which maintains the rigid annular foot on the flat supporting surface at all times for adding stability to the load supporting structure.